Smoking Article

ABSTRACT

A method of producing a smoking article is disclosed. The smoking article comprises a smoke constituent reducing technology which is capable of reducing the concentration of a smoke constituent generated by a smoking article in use. The method comprises in a first step, determining one or more first lateral regions at which, when the smoking article is in use, the smoke constituent is present at a first concentration, and one or more second lateral regions at which, when the smoking article is in use, the smoke constituent is present at a second concentration which is lower than the first concentration. In a second step, the method comprises producing a smoking article in which the smoke constituent reducing technology is targeted to reduce the concentration of the smoke constituent present at the one or more first lateral regions.

TECHNICAL FIELD

The invention relates to smoking articles and methods for making smokingarticles.

BACKGROUND

Smoke produced when smoking articles, such as cigarettes, are combustedis known to contain many different constituents. Smoking articlesfrequently comprise a filter to remove constituents from the smoke thatis drawn from the smokeable material.

SUMMARY

According to a first aspect, a method of making a smoking article isprovided. In use, the smoking article generates smoke having a smokeconstituent. The smoking article comprises a smoke constituent reducingtechnology which is capable of reducing the concentration of the smokeconstituent. The method comprises:

-   -   1) determining one or more first lateral regions at which, when        the smoking article is in use, the smoke constituent is present        at a first concentration, and one or more second lateral regions        at which, when the smoking article is in use, the smoke        constituent is present at a second concentration which is lower        than the first concentration; and,    -   2) producing a smoking article in which the smoke constituent        reducing technology is targeted to reduce the concentration of        the smoke constituent present at the one or more first lateral        regions.

According to a second aspect, a method of reducing the concentration ofa smoke constituent in the smoke produced by a smoking article isprovided. The smoking article comprises a smoke constituent reducingtechnology which is capable of reducing the concentration of the smokeconstituent in smoke. The method comprises:

-   -   1) determining one or more first lateral regions at which, when        the smoking article is in use, the smoke constituent is present        at a first concentration, and one or more second lateral regions        at which, when the smoking article is in use, the smoke        constituent is present at a second concentration which is lower        than the first concentration; and,    -   2) producing a smoking article in which the smoke constituent        reducing technology is targeted to reduce the concentration of        the smoke constituent present at the one or more first lateral        regions.

The smoke constituent reducing technology may be located in the one ormore first lateral regions.

The smoke constituent reducing technology may or may not also be locatedin the one or more second lateral regions.

The amount of smoke constituent reducing technology located in the oneor more first lateral regions may be greater than the amount located inthe one or more second lateral regions.

The smoke constituent reducing technology may be included in anysuitably appropriate amount sufficient to ensure that the concentrationof the target smoke constituent in smoke is reduced. For example, therelative amounts of smoke constituent reducing technology located in thefirst and second regions may be proportional to the relative first andsecond concentrations of the smoke constituent. In other embodiments,the relative amounts of smoke constituent reducing technology andconcentrations of the smoke constituent may not be proportional.

The smoking article may comprise a rod of smokeable material, and inthis case, the first and second lateral regions may be regions of therod of smokeable material.

The rod of smokeable material may be generally cylindrical in shape andin this case, the first and second lateral regions may be located on adiametrical line across the width of the cylinder.

The smoke reducing technology may be located at the one or more firstand/or second lateral regions. In addition, or alternatively, the smokereducing technology may be located in a region of the smoking articlewhich is away from the one or more first and/or second lateral regions.For example, the smoking article may comprise a filter and in this case,the smoke constituent reducing technology may be located within thefilter to reduce the concentration of the smoke constituent present atthe one or more first lateral regions. The filter may comprise a smokereducing technology to reduce the concentration of the smoke constituentgenerated at the one or more first lateral regions. In addition, oralternatively, the filter may contain a plurality of smoke reducingtechnologies, targeted to reduce concentrations of the smoke constituentor smoke constituents generated in both the first and second lateralregions.

The rod of smokeable material and/or the smoking article filter maycomprise portions of varying density to create controlled pressure dropregions to control airflow through the smoking article.

The smoking article may comprise a plurality of different smokeconstituent reducing technologies. For example, there may be twodifferent smoke constituent reducing technologies included in thesmoking article. In this case, the two different smoke constituentreducing technologies may be located in the same one or more firstlateral regions. Alternatively, the two different smoke constituentreducing technologies may be located in different lateral regions, whichmay include the first and/or second lateral regions, and/or alternativeregions.

For example, it may be desirable to reduce smoke constituent levels inboth the one or more first and second lateral regions. To achieve this,smoke constituent reducing technologies, which may be the same ordifferent technologies, may be included at the one or more secondlateral regions in addition to the one or more first lateral regions.

The plurality of different smoke constituent reducing technologies maybe directed towards the same or different smoke constituents.

The smoking article may comprise a co-axial rod comprising an outer rodof smokeable material circumscribed by an outer wrapper, the outer rodcomprising an inner rod of smokeable material circumscribed by an innerwrapper.

The inner wrapper may be permeable or impermeable to the passage ofsmoke constituents.

The inner wrapper may comprise the smoke constituent reducingtechnology.

The smokeable material of the inner and/or outer rod may comprise thesmoke constituent reducing technology.

The outer wrapper may be permeable or impermeable to the passage ofsmoke constituents.

The outer wrapper may comprise the smoke constituent reducingtechnology.

The inner and/or outer rods may be wrapped in a plurality of wrappers,one or more of which may comprise the smoke constituent reducingtechnology. For example, particulate sorbent material may be adhered toone or more surfaces of one or more of the wrappers. The particulatesorbent material may cover the entire surface or surfaces, or may bepresent in one or more discrete patches on the surface or surfaces ofthe one or more wrappers. In addition, or alternatively, particulatesorbent material may be present within the structure of the wrappermaterial itself.

One of the inner or outer rods may have a higher density relative to theother rod to create a region of controlled pressure drop to controlairflow through the smoking article.

The inner rod may comprise a further inner rod of smokeable materialcircumscribed by a further inner wrapper, thus forming a triple coreco-axial rod.

The smoking article may comprise a thread. For example, the smokingarticle may comprise a rod of smokeable material and the thread mayextend continuously within the smokeable material along the whole lengthof the rod of smokeable material.

The smoking article may comprise a plurality of threads, such as 2, 3,4, 5, 6, or more threads.

The thread or threads may extend along the rod of smokeable material inone or more lateral regions corresponding to the one or more firstlateral regions at which, when the smoking article is in use, the targetsmoke constituent has been found to occur in a higher concentration.

The smoking article may comprise particles that may be concentrated in alongitudinal region extending along the rod of smokeable material.

The smoking article may comprise a plurality of lateral regions in whichparticulate material is concentrated, such as 2, 3, 4, 5, 6, or moreregions.

The region or regions of particulate material may extend along the rodof smokeable material in one or more lateral regions corresponding tothe one or more first lateral regions at which, when the smoking articleis in use, the target smoke constituent has been found to occur in ahigher concentration.

The smoking article may comprise both a thread and longitudinallydisposed granular material in the same or different one or more lateralregions, targeted to the same or to different smoke constituents.

The smokeable material may be circumscribed by a wrapper and theparticles may be adhered to the inner surface of the wrapper.

The smokeable material may be circumscribed by a plurality of wrappers,one or more of which may comprise the smoke constituent reducingtechnology. For example, particulate sorbent material may be adhered toone or more surfaces of one or more of the wrappers, covering the entiresurface or surfaces, or present in one or more discrete patches on thesurface or surfaces. In addition, or alternatively, particulate sorbentmaterial may be present within the structure of the wrapper materialitself.

The smoke constituent reducing technology may be in particulate orgranular form.

The smoke constituent reducing technology may comprise an additive. Theadditive may be a sorbent or a catalyst.

The smoke constituent reducing technology may comprise a diluent.

The smoke constituent reducing technology may comprise a smokeablematerial which in use generates a concentration of the smoke constituentwhich is lower than the concentration that is produced by tobacco.

According to a third aspect, a smoking article is provided. In use, thesmoking article generates smoke having a smoke constituent. The smokingarticle comprises a smoke constituent reducing technology which iscapable of reducing the concentration of the smoke constituent. In use,the smoke constituent is present at a first concentration in one or morefirst lateral regions of the smoking article. The smoke constituent ispresent at a second concentration which is lower than the firstconcentration in one or more second lateral regions of the smokingarticle. The smoke constituent reducing technology is targeted to reducethe concentration of the smoke constituent present at the one or morefirst lateral regions.

The smoke constituent reducing technology may be located at the one ormore first lateral regions.

The smoke constituent reducing technology may additionally be positionedat the one or more second lateral regions.

The amount of smoke constituent reducing technology located in the oneor more first lateral regions may be greater than the amount located inthe one or more second lateral regions.

The smoking article may comprise a rod of smokeable material, and inthis case, the first and second lateral regions may be regions of therod of smokeable material.

The rod of smokeable material may be generally cylindrical in shape andin this case, the first and second lateral regions may be located on adiametrical line across the width of the cylinder.

According to a fourth aspect, a smoking article, which is obtainable bythe method of the first aspect, is provided.

BRIEF DESCRIPTION OF DRAWINGS

Preferred embodiments of the present invention will now be describedwith reference to the accompanying drawings (not to scale), in which:

FIG. 1a is a perspective view of a smoking article according to oneaspect of the present invention, showing in particular the co-axialconstruction of the rod of smokeable material, wherein the inner wrappercomprises a smoke constituent reducing additive;

FIG. 1b is transverse cross-sectional view of the body of the co-axialsmoking article of FIG. 1a , showing in particular, the inner wrappercomprising a smoke constituent reducing additive targeted to a lateralregion of the rod of smokeable material;

FIG. 2a is a perspective view of a smoking article according to oneaspect of the present invention, showing in particular, a threadcomprising a smoke constituent reducing additive located along alongitudinal axis of a rod of smokeable material;

FIG. 2b is transverse cross-sectional view of the body of the smokingarticle of FIG. 2a , showing in particular, a thread comprising a smokeconstituent reducing additive targeted to a central lateral region ofthe rod of smokeable material;

FIG. 3a is a perspective view of a smoking article according to oneaspect of the present invention, showing in particular, particulatesmoke constituent reducing additive located along a longitudinal axis ofa rod of smokeable material;

FIG. 3b is transverse cross-sectional view of the body of the smokingarticle of FIG. 3a , showing in particular, particulate smokeconstituent reducing additive targeted to a central lateral region ofthe rod of smokeable material;

FIG. 4 shows a number of graphs illustrating gas concentration profiles(% v/v) along the central axis of a cigarette; and,

FIGS. 5-10 show gas concentration (% v/v) and temperature distributionsin a smoking article at different time points.

DETAILED DESCRIPTION

As used herein, the term “smoking article” includes smokeable productssuch as cigarettes, cigars and cigarillos whether based on tobacco,tobacco derivatives, expanded tobacco, reconstituted tobacco or tobaccosubstitutes and also heat-not-burn products and other devices capable ofgenerating and delivering an aerosol. Such smoking articles may beprovided with a filter.

As used herein, the term “smoke constituent” includes any compound thatmay be found in the smoke produced by the combustion and/or pyrolysis oftobacco.

The smoke arising from a smoking article comprising tobacco is acomplex, dynamic mixture of more than 5000 identified compounds. Theconstituents are present in the mainstream smoke (MS), which exits themouth end of the cigarette, and are also released between puffs asconstituents of sidestream smoke (SS).

Smoking articles such as cigarettes and their formats are often namedaccording to the cigarette length: “regular” (typically in the range68-75 mm, e.g. from about 68 mm to about 72 mm), “short” or “mini” (68mm or less), “king-size” (typically in the range 75-91 mm, e.g. fromabout 79 mm to about 88 mm), “long” or “super-king” (typically in therange 91-105 mm, e.g. from about 94 mm to about 101 mm) and “ultra-long”(typically in the range from about 110 mm to about 121 mm).

Cigarettes are also named according to their circumference: “regular”(about 23-25 mm), “wide” (greater than 25 mm), “slim” (about 22-23 mm),“demi-slim” (about 19-22 mm), “super-slim” (about 16-19 mm), and“micro-slim” (less than about 16 mm). Accordingly, a cigarette in aking-size, super-slim format will, for example, have a length of about83 mm and a circumference of about 17 mm. Cigarettes in the regular,king-size format, namely with a circumference of from 23 to 25 mm and anoverall length of from 75 to 91 mm, are one of many formats commerciallymanufactured.

Smoking articles may be manufactured in any of the above formats. Thesmoking article can, for instance, be from 70 to 100 mm in length andfrom 14 to 25 mm in circumference. Indeed, the smoking article may haveany suitable size and shape as appropriate.

When a smoking article comprising a rod of smokeable material is in use,combustion and/or pyrolysis of the smokeable material may cause theproduction of a number of smoke constituents. The concentration at whichsmoke constituents occur within the burning coal (the burning tip of thecigarette) may differ when the smoking article is used under smoulderingversus puffing conditions.

When a smoking article is in use the burning portion (burning coal)advances along the rod of smokable material. By inserting a miniature ormicro-sampling probe into the smoking article in use, aerosol samplesmay be withdrawn without influencing the smoking, combustion, and/orpyrolysis processes occurring. In this way, the concentration of aparticular smoke constituent at a specific location relative to theburning portion may be determined. By repeating this process using theprobe to investigate different specific locations within the smokingarticle, a map of the concentration of the smoke constituent within thesmoking article as it is used may be produced. The concentration of thesmoke constituent may be determined as a function of smoking parameterssuch as the puff volume, puff length, and inter-puff duration.Measurements may be effected relative to a fixed position on thecigarette, such as the burn line.

The concentration of smoke constituents has been found to differ indifferent lateral regions across the rod of smokeable material. Regionsof higher and lower concentration may be located on a diametrical lineacross the width of the cylindrical rod of smokeable material.

As used herein, the “lateral” dimension of a smoking article or a rod ofsmokeable material refers to any diametric line across the width of acylindrical rod of smokeable material, wherein the width is measuredperpendicularly to the longitudinal axis of the rod.

Inclusion of Smoke Constituent Reducing Technology

In accordance with the disclosed method, in order to reduce theconcentration of a particular smoke constituent in the smoke produced bya smoking article, the skilled person must first determine theconcentration of the smoke constituent at different positions within thesmoking article when the smoking article is in use. A smoke constituentreducing technology, which is capable of reducing the concentration ofthe smoke constituent of interest, may then be incorporated within thesmoking article, targeted to reduce the concentration of the smokeconstituent at the location at which the smoke constituent has beenfound to be present at a higher concentration.

This approach has a number of advantages over previous approaches toreducing the concentration of smoke constituents in smoke. By targetingthe location of highest concentration, the greatest effect on theconcentration of the constituent of interest within the smoke may bemost effectively achieved. Moreover, the amount of smoke constituentreducing technology may be reduced because a lower amount of thetechnology may be used in areas in which the constituent is produced inthe lowest concentration, albeit optionally at an inclusion level thateffectively reduces the concentration of the smoke constituent in thatlocation.

Also, smoke constituent reducing technologies, which are more effectiveat reducing a particular smoke constituent, or classes of constituents,in the aerosol, may be selected and positioned within the smokingarticle to target these constituents. For example, the smoke constituentreducing technologies may be positioned in the region of formation ofthe smoke constituent.

Positioning a smoke constituent reducing technology within the ‘hotzones’ of combustion and/or pyrolysis in the smoking article may bekinetically favourable to smoke constituent reducing technologies suchas catalysts. The effectiveness of sorbents could also be enhanced inthe hot zone, since a target smoke constituent, whilst in the solid orliquid phase at lower temperatures, may occur in the gaseous phasewithin this zone, and thus be more readily adsorbed. Such technologies,which demonstrate enhanced activity at elevated temperatures, mayadvantageously be targeted to the hot zones to enhance the removal ordestruction of the target smoke constituents.

Conversely, other smoke constituent reducing technologies may operatemore effectively at lower temperatures and thus may advantageously betargeted to cooler areas of the smoking article, such as the filter tip.

Since the burning portion advances along the rod as the smoking articleis used, the lateral region at which the smoke constituent occurs at ahigher concentration will therefore also advance along the rod ofsmokeable material.

Thus, to optimally target the particular smoke constituent, a smokeconstituent reducing technology may be incorporated longitudinallythroughout the length of the smoking article at a particular lateralregion.

The smoke constituent reducing technology may be incorporated within therod of smokeable material and/or the filter as appropriate. The smokeconstituent reducing technology is targeted to reduce the concentrationof a particular smoke constituent at a lateral position corresponding toa position in which the smoke constituent is found in a higherconcentration.

The smoke constituent reducing technology may be included in the smokingarticle at the one or more lateral regions at which the smokeconstituent has been found to be produced at a higher concentration. Thesmoke constituent reducing technology may optionally also be included ina lower amount in a lateral region at which the smoke constituent isproduced at a lower concentration.

Location of the Smoke Constituent Reducing Technology

The smoke constituent reducing technology may be incorporated within therod of smokeable material and/or the filter as appropriate.

The smoke constituent reducing technology may be located at the one ormore first lateral regions at which, in use, the smoke constituent hasbeen found to be present at a higher concentration, relative to theconcentration at another region of the smoking article.

The smoke constituent reducing technology may be located in a greateramount at a first lateral region at which, in use, the smoke constituenthas been found to be present at a higher concentration, and, in a lesseramount, at a second lateral region at which, in use, the smokeconstituent has been found to be present at a lower concentration.

The smoke reducing technology may be located in a region of the smokingarticle which is away from the one or more first lateral regions atwhich, in use, the smoke constituent has been found to be present at ahigher concentration. In this case, the smoke constituent reducingtechnology may be targeted to reduce the concentration of the smokeconstituent at the one or more first lateral regions at which, in use,the smoke constituent has been found to be present at a higherconcentration, relative to the concentration at another region of thesmoking article.

The smoke reducing technology may be located in a region of the smokingarticle which is away from the one or more second lateral regions atwhich, in use, the smoke constituent has been found to be present at alower concentration.

Several different smoke reducing technologies may be used in a smokingarticle, positioned in the same or different lateral regions.

It has now been discovered that the incorporation of smoke constituentreducing technologies longitudinally in different lateral positionswithin a smoking article reduces the level of target smoke constituentsgenerated in use in the smoke.

Depending on the particular smoke constituent reducing technology, thetechnology may be included in the rod of smokeable material, in thesmoking article filter, or in both the rod of smokeable material and thesmoking article filter.

A number of smoke constituent reducing technologies may only be suitablefor incorporation into the filter of the smoking article. Porous polymerresins have been designed for trapping volatile and semivolatilesubstances from air, for example Tenax TA®. Other sorbent polymericresins are available, for example, molecularly imprinted polymers, andcommonly used ion exchange or chelating resins, such as Diailon® CR-20.These materials are unsuitable for use within the smoking material, dueto their thermal instability and potential degradation in the ‘hot zone’of the smoking article.

Smoke Constituents

In some embodiments, reductions in mainstream smoke constituents mayinclude, but are not restricted to, one or more of the substances knownin the art as ‘Hoffmann analytes’. This term relates to a group ofconstituents of mainstream smoke generated from a smoking article, andincludes: aromatic amines; phenols; carbonyls; polycyclic aromatichydrocarbons; acrylonitrile; volatile hydrocarbons such as isoprene,styrene, benzene, and 1,3-butadiene; nitrogen heterocyclics such aspyridine; quinoline; tobacco specific nitrosamines (TSNAs) such asN′-nitrosoanabasine (NAB), N′-nitrosoanatabine (NAT),4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) andN′-nitrosonornicotine (NNN); inorganic compounds such as ammonia,hydrogen cyanide, nitric oxide and carbon monoxide; and heavy metalssuch as mercury, cadmium, lead, chromium and nickel.

The smoke constituents targeted by the smoke constituent reducingtechnology may include, but are not restricted to, one or a combinationof: aromatic amines, such as i-aminonaphthalene, 2-aminonaphthalene,3-aminobiphenyl, 4-aminobiphenyl; phenols, such as phenol, o-cresol,m-cresol, p-cresol, catechol, resorcinol, hydroquinone; carbonyls, suchas formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde,crotonaldehyde, methyl ethyl ketone, butyraldehyde; polycyclic aromatichydrocarbons such as benzo(a)pyrene, naphthalene; aromatic hydrocarbonssuch as, toluene, benzene; acrylonitrile; volatile hydrocarbons such asisoprene, styrene and 1,3-butadiene; nitrogen heterocyclics such aspyridine, quinoline; tobacco specific nitrosamines (TSNAs) such asN′-nitrosoanabasine (NAB), N′-nitrosoanatabine (NAT),4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) andN′-nitrosonornicotine (NNN); inorganic compounds such as ammonia,hydrogen cyanide, nitric oxide and carbon monoxide; and heavy metalssuch as mercury, cadmium, lead, chromium and nickel.

Smoke Constituent Reducing Technologies

The smoke constituent reducing technology may comprise any technologythat is capable of being incorporated into a smoking article andreducing the concentration of a constituent of the smoke produced in useby the smoking article. The smoke constituent reducing technology may bespecific for a particular smoke constituent. Alternatively, the smokeconstituent reducing technology may have a broad capacity to interactwith various smoke constituents or classes of smoke constituents.

The smoke constituent reducing technology may comprise any technologythat is capable of reducing the concentration of a smoke constituent insmoke. For example, the smoke constituent reducing technology maycomprise an additive, such as a sorbent or a catalyst, a diluent, or amodified or synthetic smokeable material. By way of examples, a numberof suitable smoke constituent reducing technologies are discussed below.

Additives

The smoke constituent reducing technology may be a smoke constituentreducing additive. The smoke constituent reducing additive may be anyadditive that is capable of reducing the concentration of a smokeconstituent in smoke. For example, the smoke constituent reducingadditive may comprise a sorbent or a catalyst.

The additive may be in any suitable form. For example, the additive maybe particulate or in a processed form, such as in the form of amonolith.

The smoke constituent reducing technology may be a particulate additive,the particles of which are concentrated in one or more longitudinallyextending regions within the filter material or the rod of smokeablematerial. The smoke constituent reducing technology may be an additivewhich is incorporated into one or more of the paper wrappers of thesmoking article.

The additive may be adhered to one or more surfaces of one or more ofthe wrappers. The additive may cover the entire surface of one side ofthe wrapper, or the entire surface of both sides of the wrapper.Alternatively, the additive may be present in one or more discretepatches on the wrapper, which may be on one side of the wrapper, or onboth sides of the wrapper. The one or more patch or patches may have anyshape or configuration. For example, the patch or patches may be in theform of circumferential bands around the smoking article, orlongitudinal stripes along the length of the smoking article. Suchwrappers are discussed, for example, in WO 2007/104908.

In addition, or alternatively, particulate additive material may bepresent within the structure of the wrapper material itself, asdescribed, for example, in WO 2010/043475. For example, the additive maybe a particulate sorbent material such as active carbon which isincorporated into the structure of the paper during manufacture of thepaper. The sorbent may carry a further smoke constituent reducingtechnology, for example, the sorbent may be impregnated with a diluent,and/or the sorbent may serve as a carrier for a catalyst.

The wrapper material may be a paper material. Alternatively, the wrappermay comprise a reconstituted tobacco material. The reconstituted tobaccomaterial may comprise particulate additive material. The additive may beapplied to the reconstituted tobacco material using the same approachesas described above in respect of paper wrappers. For example, theadditive may be applied to the surface of the material, and/or theadditive may be incorporated within the structure of the reconstitutedtobacco material itself. Such a material is described, for example, inWO 99/38396.

The additive may be adhered to one or more threads which extendlongitudinally along the length of the smoking article filter and/or rodof smokeable material. Such threads are described, for example, in WO96/14762, WO 2009/010380, and WO 2010/032032.

The smoke constituent reducing additive may be coated or otherwisecontained in a protective environment to prolong shelf life. Forexample, the smoke constituent reducing additive may comprise anencapsulated additive. The protective environment utilised to prolongshelf life of the smoke constituent reducing additive should not inhibitthe activity of the material, which may be capable of being released oractivated by mechanisms encountered during the smoking process. Forexample, the additive may be activated by heat or by interaction with asmoke constituent such as water.

Sorbents

A “sorbent” is a substance that can condense or hold molecules of othersubstances on its surface, and/or can take up other substances, i.e.,through penetration of the other substances into its inner structure, orinto its pores. Accordingly, the term “sorbent” as used herein refers toan adsorbent, an absorbent, or a substance that can function as both anadsorbent and an absorbent. The sorbent may be any relatively highsurface area material to which the smoke constituent may adsorb, andwhich is thereby capable of reducing the concentration of a smokeconstituent in smoke.

The smoke constituent reducing additive may include one or a combinationof any suitable sorbents, including, for example, carbon (such asactivated carbon), zeolite, silica gel, silica, silicates,alumino-silicates, sepiolite, clay, aluminium oxide.

In particular, the smoke constituent reducing additive may be anactivated carbon material. The activated carbon material may be derivedfrom vegetable matter (such as coconut shells), as described, forexample, in WO 2012/032349. Alternatively, the activated carbon materialmay be derived from a resin (such as a phenolic resin), for example, asdescribed in WO 2006/103404.

The activated carbon material may be surface modified to improve thespecificity of the material for a particular smoke constituent or classof smoke constituents. The presence of particular chemical groups on thesurface of the porous carbon material may affect the adsorptionproperties of the material. For example, activated carbon materialprepared using a nitrogen-donating agent may enhance the selectiveadsorption of smoke constituents including low molecular weightaldehydes and HCN, as described in WO 2012/098405. Likewise, activatedcarbon material prepared using magnesium carbonate may enhance theselective adsorption of acrolein, formaldehyde and HCN, as described inWO 2012/160354. The hydrophobicity and/or hydrophilicity of the surfaceof the sorbent material may be modified to provide further control ofthe sorbent properties and improve the specificity of the material for aparticular smoke constituent or class of smoke constituents.

The sorbent may comprise micropores (<2 nm pore diameter), mesopores(2-50 nm diameter), and/or macropores (diameters greater than 50 nm).The sorbent may be modified to adjust the pore structure, such as toincrease the mesoporosity, as described, for example, in WO 2010/103323and WO 2012/032349.

The sorbent may be present in the smoking article in granular orparticulate form, for example, as described in WO 2006/103404.

The sorbent may be a carbonaceous dried gel, for example of the typedescribed in WO 2011/030151. Such dried gels are porous, solid-statematerials obtained from gels or sol-gels whose liquid component has beenremoved and replaced with a gas, which have then been pyrolysed and/orcarbonized. They can be classified according to the manner of drying andinclude carbon xerogels, aerogels and cryogels.

Xerogels are typically formed using an evaporative drying stage underambient pressure conditions. They generally have a monolithic internalstructure, resembling a rigid, low density foam having, for example,60-90% air by volume. Aerogels, on the other hand, can be produced usingother methods such as supercritical drying. They contract less thanxerogels during the drying stage and so tend to have an even lowerdensity (90-99% air by volume for example). Cryogels may be producedusing freeze drying techniques.

The sorbent may comprise carbon material in the form of carbon nanotubesand/or graphene.

The sorbent may comprise a Metal Organic Framework (MOF).

The sorbent may be coated. For example, the sorbent may comprise analginate-coated porous carbon material. In addition, or alternatively,the sorbent may carry a diluent, for example as described in WO2010/125386.

The sorbent may be in a processed form. In particular, the sorbent maybe in the form of a monolith, for example as described in WO2012/168699.

The sorbent may comprise an adsorption promoter. A suitable adsorptionpromoter may comprise a hydrophilic organic substance and both ahydrogen bond donor and acceptor. Such an adsorption promoter mayincrease the affinity of the sorbent for phenol, as discussed in WO2011/015861.

Catalysts

The smoke constituent reducing additive may be a catalyst. A “catalyst”is a substance that modifies and increases the rate of a chemicalreaction without being consumed in the process. The catalyst may becapable of promoting the conversion of a smoke constituent into one ormore different substances. In addition, or alternatively, the catalystmay convert a compound, which would otherwise be a precursor of thetarget smoke constituent, into an alternative compound, thus preventingthe formation of the smoke constituent.

Catalysts may comprise, for example, metals, such as transition metalsor rare earth metals, metal salts, or metal oxides. In some embodiments,a catalyst capable of facilitating the oxidation of CO to CO₂ may beused. Suitable CO catalysts include metals, such as transition metals orrare earth metals, metal salts, metal oxides or combinations thereof. Inparticular, a catalyst capable of facilitating the oxidation of CO toCO₂ may comprise iron oxide and/or a hopcalite (copper manganese oxide).

The catalyst may be placed on a support or carrier made of graphite,activated carbon, copper oxide, alumina or titania, for example. Thecarrier may be uniformly coated with the catalyst, the loading beingfrom about 0.1% to about 10%, based on the total dry weight of thecoated support or carrier.

The catalyst may be provided in the form of coarse, fine or ultrafineparticles. Coarse particles are particles having a diameter of about 2.5μm to about 200 μm. Fine particles are particles having a diameter ofabout 100 nm to about 2.5 μm. Ultrafine particles are particles having adiameter of less than about 100 nm. Typically, the particles have anaverage particle size of between about 1 nm and 100 μm, for example,between about 10 nm to about 10 μm. Particles of catalyst may beobtained commercially.

Molecularly Imprinted Polymers

The additive may comprise a molecularly imprinted polymer (MIP).

The MIP may be specific for one or more than smoke constituents. Forexample the MIP may be capable of specifically binding tobacco specificnitrosamines, as described, for example, in WO 2008/068153.

Diluents

The smoke constituent reducing technology may comprise a diluent. A“diluent” acts as a direct replacement of a smoke constituent, andthereby reduces the concentration of the smoke constituent in the smoke.

The diluent may be included in the smokeable material. For example, thediluent may be bound to the smokeable material and/or incorporatedwithin the cellular structure of the material, as described in WO03/092416 and WO 2012/010880.

The diluent may be incorporated into the wrapper of the smokeablematerial. For example, the diluent may be carried by a sorbent materialwhich is incorporated into the wrapper. Such wrappers are described, forexample, in WO 2010/043475.

The diluent may be impregnated into particulate porous material, asdescribed, for example, in WO 2010/125386.

The diluent may be in the form of particles of diluent encapsulated witha barrier material, as discussed, for example, in WO 2010/125385.

Suitable diluents include aerosol forming means utilising a wide rangeof classes of substances known to those skilled in the art. For example,polyhydric alcohols, such as glycerol, propylene glycol, sorbitol andtriethylene glycol; esters, such as diacetin, triethyl citrate,isopropyl myristate or triacetin, high boiling point hydrocarbons, orlactic acid. A combination of diluents may be used, in equal ordiffering proportions.

Other Additives

The smoke constituent reducing technology may comprise a chemicalreactant which may reduce the concentration of a smoke constituent byreacting with the constituent. The reaction mechanism may comprise achemical combination and/or a chemical combination followed by adecomposition.

The smoke constituent reducing technology may comprise an additive whichadjusts the temperature of combustion of the smokeable material.

For example, the additive may act to either decrease the thermal energyproduced during the smoking process by passively absorbing energy, or itmay actively influence smoking thermal energy by itself undergoing anendothermic promoted change (wherein thermal energy may be taken out ofthe smoking process) or an exothermic promoted change (wherein thermalenergy may be contributed to the smoking process). In this way, due tothe adjusted temperature, the chemical reactions occurring as thesmokeable material combusts or pyrolyses may be adjusted, and differentsmoke constituents may be produced, and as a result, the concentrationof target smoke constituents, or classes of constituents, may bereduced.

An example of a material that may be used to increase the temperature isa carbon material such as particulate charcoal material.

Similarly, other additives may be used to change the conditions withinthe smokeable material and thus adjust the chemical reactions occurring.Suitable examples may include oxidising and reducing agents.

Ceramic Wrapper Materials

The smoke constituent reducing technology may comprise a ceramic-basedwrapper. The ceramic-based wrapper may be capable of trapping smokeconstituents. In addition, or alternatively, the ceramic-based wrappermay be thicker than a conventional wrapper and thus displace aproportion of the smokeable material. Ceramic-based wrappers arediscussed, for example, in WO 01/41590.

The ceramic-based wrapper may comprise a smoke constituent reducingadditive which is capable of reducing the concentration of a smokeconstituent in smoke. The additive may be incorporated together with theceramic filler into the structure of the wrapper. In addition, oralternatively, the additive may be applied to the surface of thewrapper.

The ceramic-based wrapper may comprise a proportion of a ceramic fillerof predefined shape, a binder, optionally a burn additive and optionallyan ash improver.

The predefined shape of the ceramic filler is such that the wrapper hasa porous self-sustaining structure and when combusted the wrapper losesits structural integrity. For example, the ceramic filler may bespherical or substantially spherical, oval or substantially oval, oranother irregular shape approximating thereto.

Advantageously the ceramic filler has a particle size in the range of2-90 μm, more preferably 2-75 μm and even more preferably 25-70 μm, suchas about 50 μm.

The ceramic filler may be an insoluble or low solubility metal oxide ormetal salt, and may be a thermally stable metal oxide or metal salt. Theceramic filler may be one or more of alumina, silica, analumino-silicate, silicon carbide, stabilised or un-stabilised zirconiumoxide, zircon, garnet, feldspar, or other materials known to the skilledman and having the necessary particle size or other suitable ceramicmaterials having been milled to the necessary size or shape.

The ceramic filler may be present at greater than 40% by weight of thedry materials in the slurry producing the wrapper, and is morepreferably present in the range of 50-95%, and more preferably 70-90%.

The binder functions to cement the particles of ceramic filler together.The binder may be an organic binder, and may be one or more of analginate, (such as calcium alginate or propylene glycol alginate), agum, a cellulose (modified or natural), a pectin or pectinaceous binder,starch, or the Group I or II metal salts of these binders, such assodium carboxymethylcellulose or sodium alginate. In addition oralternatively, the binder may be an inorganic binder, and may be one ormore of activated alumina, aluminium silicate, magnesium silicate or aninert clay.

A burn additive may be included in the ceramic-based wrapper to improvethe burn characteristics of the wrapper. The burn additive may bepresent in the range of 1-15% by weight of the dry materials in theslurry used to produce the wrapper and is more preferably <10% and evenmore preferably <5%, such as in the range of 2-5%. The burn additive isa burn promoter. Suitable burn additives may be selected from one ormore of salts of Group I or II metals such as acetates, citrates andother burn promoters known to the skilled person.

An ash improver may be included in the ceramic-based wrapper to providebridging means or packing improvement means between the ceramic fillerparticles. The wrapper should burn down and ash in a manner similar tothat of a conventional combustible smoking article. The components ofthe wrapper, and in particular the ceramic filler and ash improver, havea particle size and/or shape such that their combination provides thenecessary strength in the wrapper before combustion but loses suchstrength during combustion in order to provide acceptable ashing of thecombusted products.

The inorganic ash improver suitably has a platelet morphology andmaterials that have the appropriate platelet morphology compared to themore rounded shape of the ceramic filler, include one or more of mica,chalk, perlite, clays, such as, for example, vermiculite; kaolinites andtalcs. The ash improver may in addition or alternatively be a materialwith a very small particle size such that particles thereof bridge thevoids between the larger ceramic filler particles.

In some embodiments, the ceramic-based wrapper may be produced usingknown manufacturing techniques. In particular, ceramic-based wrappersmay be formed by producing a thick slurry of the wrapper components,coating the slurry about a rotating mandrel, and removing excessmoisture by physical or chemical means. Alternatively, the slurry may becast as a sheet on a drum or band caster, or extruded as a hollow tube,through a “torpedo” die-head, for example, which has a solid centralsection, or extruded as a sheet material.

The ceramic-based wrapper may have a thickness of 0.1-4 mm, and maypreferably be 1.5-3.5 mm, such as 2.1-2.8 mm in thickness.

Smokeable Materials

The smoke constituent reducing technology may comprise the use of analternative or modified smokeable material. For example, some smokeablematerials may generate lower amounts of a smoke constituent than othersand the smoke constituent reducing technology may comprise a smokeablematerial that is known to generate a low amount of a particular smokeconstituent. Thus, a smokeable material that is known to generate a lowamount of a smoke constituent may be incorporated into specific lateralregions of a rod of smokeable material. Smokeable materials, includingtobacco and tobacco reconstituted materials, and tobacco-free materials,which generate low amounts of a smoke constituent, may be used.

The smoke constituent reducing technology may comprise a modifiedtobacco material. The tobacco may be modified to reduce the amount ofsmoke constituent produced upon combustion or pyrolysis of the tobacco.The tobacco may be modified by addition of modifying agents. Forexample, salts such as inorganic salts may be added to tobacco to alterthe type and concentrations of smoke constituents produced uponcombustion or pyrolysis of the material. Suitable metal salts includezinc chloride and magnesium chloride.

The tobacco may be modified by the addition of smoke diluents on itssurface and/or within its cellular structure, as described for examplein WO 2012/010880. The tobacco may comprise a diluent and be coated witha barrier material, as described for example, in WO 2010/125287.

The smoke constituent reducing technology may comprise a tobaccosubstitute material such as a smokeable filler material. The smokeablefiller material may comprise no tobacco, and may comprise for example, afiller such as chalk, and a binder. The smokeable filler material may bea foamed smokeable filler material. Such a material is described, forexample, in WO 2005/044026.

The smoke constituent reducing technology may comprise a smokeablematerial such as tobacco that is heated to cause the volatilisation ofthe low boiling point components but avoiding pyrolysis or combustion ofthe material or volatiles, and thereby reducing the concentration ofsmoke constituents.

Materials comprising no tobacco, such as chalk particles bound togetherwith a suitable binder such as sodium alginate to form a sheet orextrudate, which may be subsequently cut or shredded may also be used asa smoke constituent reducing technology. These materials may alsocontain other ingredients which act as aerosol forming substances thatare released on combustion or by thermal means. Such sheets aredescribed, for example, in WO 03/092416.

The smoke constituent reducing technology may be added to, and/orcarried by, a smokeable element comprising a porous material such as aporous carbon material. The technology may be carried within the poresof the porous material and may be released or activated when the smokingarticle is in use. The technology may be released by any suitable means,for example, the temperature, pH, moisture content, or other property ofthe smoke or combustion of the smokeable material may induce the releaseand/or activation of the technology. Such a material is described, forexample, in WO 2013/045944.

Any of the smoke constituent reducing technologies may be used incombination with another smokeable material, which may be another smokeconstituent reducing technology.

The smokable material may comprise tobacco material. The tobaccomaterial may comprise one or more of stem, lamina, and tobacco dust. Thetobacco material may comprise one or more of the following types:Virginia or flue-cured tobacco, Burley tobacco, Oriental tobacco,reconstituted tobacco, and expanded tobacco. The smokable material maycomprise a blend of tobacco material, and may, for example, compriseVirginia tobacco, Burley tobacco, Oriental tobacco, reconstitutedtobacco, expanded tobacco, such as dry ice expanded tobacco, and stem.The smokable material may comprise processed tobacco materials, such asvolume expanded or puffed tobacco, processed tobacco stems, such ascut-rolled or cut-puffed stems, reconstituted tobacco materials, blendsthereof, and the like.

The smokable material may comprise a humectant. The humectant maycomprise, for example, glycerol, triethylene glycol and/or propyleneglycol.

The smokable material may further comprise a colourant and/or aflavourant. As used herein, the terms “flavour” and “flavourant” referto materials which, where local regulations permit, may be used tocreate a desired taste or aroma in a product for adult consumers. Thecolourant may be used to darken the material and the flavourant may beused to impart a particular flavour. Finely ground, granulated orhomogenised tobacco may be used. Industry approved food colourants mayalso be used, such as E150a (caramel), E151 (brilliant black BN), E153vegetable carbon or E155 (brown HT). Suitable flavourants includementhol and vanillin, for example.

Control of Smoke Flow

The smoking article may be configured such that different internalregions offer different levels of resistance to the passage of smoke,thereby providing different levels of pressure drop in the differentregions. This may be achieved for example, by the use of differentsmokeable materials, having different inherent densities, or differentpacking densities, in different regions of the smoking article. In use,a greater pressure drop will be established as smoke is drawn throughthe region of higher density, as described, for example, in WO2012/016795.

It may be advantageous to arrange smoking articles in this way becausesmoke that is drawn through the region of greater pressure drop may movemore slowly and therefore may be subject to an increased action from thesmoke constituent reducing technology within that region. This may beparticularly effective in embodiments in which the smoke constituentreducing technology comprises an additive such as a sorbent or acatalyst.

Furthermore, different combinations of smoke constituents may beproduced under different pressures. Thus, the use of compartments havingdifferent pressure drops may directly reduce the level of production ofthe smoke constituent.

Specific Embodiments

A description of a suitable methodology to determine distributionconcentrations of smoke constituents with respect to lateral andlongitudinal regions of a smoking article is given in the Examples.

The concentration of smoke constituents can be measured by inserting aminiature or micro-sampling probe into the smoking article at knownspatial positions. Smoke samples may then be collected withoutinfluencing the smoking, combustion, and/or pyrolysis processes that areoccurring as the smoking article is used. The concentration of smokeconstituents may thus be determined in real time, for example, by massspectrometry as described in the Examples.

Smoke constituents have been found to be produced at differentconcentrations in different regions of the smoking article when thesmoking article is in use. In accordance with the disclosed method, asmoke constituent reducing technology, which is capable of reducing theconcentration of the smoke constituent, is targeted to reduce theconcentration of the smoke constituent present at the one or more firstlateral regions. For example, the smoke constituent reducing technologymay be incorporated within the smoking article at a lateral positioncorresponding to the location at which the smoke constituent has beenfound to be present at a higher concentration relative to theconcentration at another lateral region.

The smoke constituent reducing technology may be incorporated into asmoking article using any suitable method. A number of approaches, whichhave been found to be suitable, are shown in the accompanying Figuresand discussed below.

FIG. 1a, 1b is a schematic illustration of a smoking article 101according to an embodiment of the invention.

In the embodiment shown in FIG. 1a, 1b , the smoke constituent reducingtechnology is targeted to a lateral region, which is an intermediateannular region, located between the centre and the circumferentialsurface of the rod of smokeable material.

FIG. 1a, 1b shows a smoking article 101 comprising a filter 102 and arod of smokeable material 103. The filter 102 is at the mouth end of thesmoking article 101. The rod of smokeable material 103 is in the form ofa cylindrical rod, and the circumferential surface of the smokeablematerial 103 is wrapped in a wrapping material 104, such as a cigarettepaper.

The filter 102 comprises a substantially cylindrical plug of filtermaterial 105 wrapped in a plugwrap 106 around its circumferentialsurface. The wrapped rod of smokeable material 103 is aligned with thefilter 102, such that the end of the rod of smokeable material abuts theend of the filter 102. The rod of smokeable material 103 is joined tothe filter 102 by tipping material 107 which overlays the filter 102 andpartially overlays the wrapping material 104.

In the embodiment shown, the smoke constituent reducing technology 109is located within the rod of smokeable material 103. In otherembodiments, a smoke constituent reducing technology, which may be thesame or a different technology, may in addition or alternatively belocated within the filter 102 of the smoking article 101.

The rod of smokeable material 103 is of co-axial construction and has aninner rod no, an inner wrapper in, and an outer rod 112. The outer rodis wrapped in the wrapping material 104.

The inner rod 110 of the co-axial arrangement contains a first smokeablematerial 114, which in the embodiment shown is cut tobacco material, andmay in general comprise any suitable smokeable material or blend.

The inner rod 110 is circumscribed by the inner wrapper 111, as shown inFIG. 1a, 1b . The inner wrapper 111 is, in the present example, acigarette paper.

The inner rod 110 and inner wrapper 111 are circumscribed by the outerrod 112, as shown in FIG. 1a, 1b . In the embodiment shown, the outerrod 112 comprises a second smokeable material 115, comprising cuttobacco material, which is combusted during use. The second smokeablematerial 115 may in general comprise any suitable smokeable material orblend.

As shown in FIG. 1a, 1b , the outer rod 112 is circumscribed by theouter wrapper 104. In the embodiment shown, the outer wrapper 104 is acigarette paper.

The construction of the inner rod 110, inner wrapper 111, outer rod 112and outer wrapper 104, may for example, be achieved through existingco-axial cigarette manufacturing technology.

In use, combustion of the inner and outer rods 110, 112 generates smokewhich is drawn through the smoking article 101.

The rod of smokeable material comprises a smoke constituent reducingtechnology 109 which is capable of reducing the concentration of aparticular target smoke constituent in smoke. In other embodiments, thesmoke constituent reducing technology may be capable of reducing theconcentration of several target smoke constituents.

In the embodiment shown in FIG. 1a, 1b , the smoke constituent reducingtechnology comprises particles of a smoke constituent reducing additive109. The additive 109 is capable of adsorbing a target smoke constituentfrom smoke.

Specifically, the inner wrapper 111 comprises a smoke constituentreducing additive 109, as shown in FIG. 1b . In this case, the additiveis particulate activated carbon material, and is adhered to, andcompletely covers, both surfaces of the wrapper 111. Due to beingadhered to the inner wrapper iii, the additive 109 is targeted to aposition within the rod of smokeable material 103 corresponding to anintermediate annular region. The targeted region may be varied byadjusting the position of the inner wrapper 111, for example, byadjusting the relative diameters of the inner and outer rods 110, 112.

In the embodiment shown, the additive 109 is adhered to the wrapper 111as described in WO 2007/104908 and is present on both faces of the innerwrapper 111. Any suitable method may be used to apply the additive tothe wrapper 111. In other embodiments, the additive 109 may in addition,or alternatively, be incorporated within the structure of the wrapper111, as described in WO 2010/043475.

The inner wrapper 111 is a paper wrapper material. In other embodiments,however, the wrapper 111 may comprise an alternative material, such as areconstituted tobacco material, which may comprise particulate sorbentmaterial as described in WO 99/38396.

By means of the arrangement shown in FIG. 1, a smoke constituentreducing additive may be targeted to specific lateral regions with therod of smokeable material 103. Specifically, the inner and outer rods110, 112, may be constructed so that the inner wrapper 111 substantiallycoincides with the lateral regions at which a particular smokeconstituent has been found to occur at a concentration which is higherthan the concentration found in another lateral region.

In use, combustion of the rod of smokeable material 103 generates smokewhich is drawn through the smoking article 101. Due to the targetedpositioning of the smoke constituent reducing additive 109 within thesmoking article 101, the concentration in the smoke of a particularsmoke constituent, which has previously been found to be produced at ahigh concentration in the lateral region of the smokeable material 103targeted by the inner wrapper 111, may be reduced.

In some embodiments, the inner wrapper 111 may comprise reconstitutedtobacco sheet material. The reconstituted tobacco sheet material mayhave a similar thickness to a paper wrapper, or may be of a differentthickness, such as, for example, thicker. In embodiments in which thewrapper is thicker than a paper wrapper, the reconstituted tobacco sheetmaterial 111 may function as a smoke constituent reducing technology bydisplacing a proportion of the first and/or second smokeable material114, 115. In addition, or alternatively, due to the composition of thereconstituted tobacco sheet material 111, the material may produce areduced amount of the smoke constituent when combusted or pyrolysed. Forexample, the reconstituted tobacco sheet material may comprise asorbent, as described in WO 99/38396.

The wrapper may also be modified in other ways in order to reduce theconcentration of a specific smoke constituent. For example, the wrappermay comprise a diluent, as described in WO 2010/043475.

The inner rod wrapper 111 may be permeable to smoke and smokeconstituents, or may be impermeable, and may prevent the passage ofsmoke and smoke constituents.

In some embodiments, for example, where it is desired to target smokeconstituents in other lateral regions of the smoking article, thesmokeable material of the inner rod 110 and/or outer rod 112 maycomprise a smoke constituent reducing technology.

For example, in some embodiments, in addition to, or as an alternativeto being applied to one or more faces of the inner wrapper 111, ordispersed throughout the body of the wrapper material, the additive 109may be applied to the smokeable material 114, 115 of the inner and/orouter rod 110, 112. The additive may be bound to the smokeable materialor simply distributed within the smokeable material, for example, asdescribed in WO 2011/033121. In these embodiments, the inner wrapper 111may serve to segregate lateral regions of the rod of smokeable material,wherein different lateral regions may comprise different concentrationsof additive 109.

In addition, or alternatively, the inner rod no and/or outer rod 112 maycomprise different smokeable materials or different blends of smokeablematerial. Upon combustion, the different smokeable materials in theinner and outer rods 110, 112, may give rise to different quantities ofa particular smoke constituent. One or both of the smokeable materials110, 112, may comprise a smoke constituent reducing technology, whichmay be selected to produce a lower concentration of the particulartarget smoke constituent. In addition, or alternatively, a smokeconstituent reducing additive 109 may be applied to one or both of thedifferent smokeable materials.

For example, in some embodiments, the inner rod no may comprise one ormore tobacco substitute materials such as a smokeable filler material.Such tobacco substitute materials may in use generate reduced levels ofa target smoke constituent and may thereby constitute a tobaccoconstituent reducing technology, which is targeted to a lateral regionwhich is a central region of the smoking article, by means of theco-axial construction of the rod of smokeable material.

In other embodiments, the outer rod 112 may in addition, oralternatively, contain one or more tobacco substitute materials such asa smokeable filler material. Such tobacco substitute materials may inuse generate reduced levels of a target smoke constituent and maythereby constitute a tobacco constituent reducing technology, which istargeted to a peripheral lateral region by means of the co-axialconstruction of the rod of smokeable material.

The smokeable filler materials that may be used in the inner rod noand/or outer rod 112 may comprise an inorganic filler, such as describedin WO 03/092416. The smokeable filler material may in addition, oralternatively, be a foamed smokeable filler material, such as describedin WO 2005/044026.

The inner or outer rod 110, 112 may comprise a smokeable material otherthan tobacco or a tobacco substitute material. For example, thesmokeable material of the inner or outer rod 110, 112 may comprise asmokeable element. A suitable smokeable element may comprise particlesof a porous carrier material, bound together by means of a binder,wherein the binder is a combustible binder. The smokeable element mayfurther comprise an agent, which may be a flavourant, such as a tobaccoextract, carried by the porous carrier material. Such a smokeableelement is described in WO 2013/045944.

In addition, or alternatively, the smoking article 101 may be arrangedsuch the first or second smokeable material is heated to causevolatilisation of low boiling point components within the smokeablematerial, while avoiding pyrolysis or combustion of the smokeablematerial or volatile smokeable material constituents. Such anarrangement is described, for example in WO 2012/016795.

To improve the targeting of the smoke constituent reducing technology tothe one or more lateral regions at which the particular smokeconstituent is concentrated, the inner rod 110 may be symmetrical orasymmetrical. For example, in cross-section, the inner rod 110 may becircular, or may have any non-circular shape, such as for example, oval,square, rectangular, or triangular. In addition, or alternatively, theinner rod 110 may be positioned off-centred within the outer rod 112,such that the longitudinal axes of the two rods 110, 112 do notcoincide.

In some embodiments, the inner rod 110 comprises one or more furtherinner rod(s). In this way, smoke constituent reducing technologies canbe targeted towards an increased number of lateral locations within thesmoking article.

In some embodiments, the smoking article is configured such that theinner and outer rods 110, 112, offer different levels of resistance tothe passage of smoke. Thus, there are different levels of pressure dropin the different compartments. This may be achieved for example, byconstructing one of the inner and outer rods at a higher density thanthe other rod. This will create a (greater) pressure drop in the rod ofhigher density. Smoke drawn through the compartment which has a greaterpressure drop may move more slowly and therefore may be subject to anincreased action from the smoke constituent reducing technology withinthat compartment. This may be particularly effective in embodiments inwhich the smoke constituent reducing technology comprises an additivesuch as a sorbent or a catalyst.

Furthermore, different combinations of smoke constituents may beproduced under different pressures. Thus, the use of compartments havingdifferent pressure drops may directly reduce the level of production ofthe smoke constituent.

In some embodiments, the outer wrapper 104 may comprise the smokeconstituent reducing technology. This may be in addition, or as analternative, to the use of a smoke constituent reducing technology inthe first and/or second smokeable materials 114, 115, and/or the innerwrapper 111. Such an arrangement may be particularly suitable fortargeting smoke constituents that have been found to be produced at ahigher concentration in peripheral regions, nearer to thecircumferential surface of the outer wrapper 104 of the smoking article101.

For example, the outer wrapper 104 may comprise a smoke constituentreducing technology in the form of an additive, such as a sorbent or acatalyst, adhered to the inner face of the wrapper 104, such asdescribed in WO 2007/104908. In addition, or alternatively, the outerwrapper 104 may comprise reconstituted tobacco sheet material, asdescribed above in respect of the inner wrapper 111, and in WO 99/38396.

In some embodiments the smoking article 101 may comprise a ceramic-basedwrapper, such as described in WO 01/41590. The ceramic-based wrapper maybe capable of trapping smoke constituents. In addition, oralternatively, the ceramic-based wrapper may be thicker than aconventional wrapper and thus displace or replace a proportion of thesecond smokeable material 115.

In some embodiments, the ceramic-based wrapper may comprise a smokeconstituent reducing additive which is capable of reducing theconcentration of a smoke constituent in smoke. In some embodiments, theadditive may be incorporated together with the ceramic filler into thestructure of the wrapper. In addition, or alternatively, the additivemay be applied to the surface of the wrapper 104.

In accordance with embodiments of the type shown in FIG. 1a, 1b , thearrangement of two or more smoke constituent reducing technologies,which may be the same or different technologies, at two or more lateralpositions in the smoking article may be used to facilitate reductions ofsmoke constituents at lateral positions where smoke constituents may begenerated at both higher and lower concentrations. Specifically, thearrangement of the co-axial smoking article shown in FIG. 1 allows theaccurate incorporation of one or more different smoke constituentreducing technologies into specific location(s) in the smoking article.For example, as described above, the inner and/or outer wrappers 111,104, and/or the first and/or second smokeable material 114, 115, or anycombination of these parts, may comprise one or more smoke constituentreducing technologies. The location of the technologies may be easilyand accurately controlled, by adjusting the materials used and thediameter of the inner rod 110, to target one or more smoke constituentsbased on prior measurements of the concentration of the smokeconstituents present at different locations when the smoking article isin use.

FIG. 2a, 2b is a schematic illustration of a smoking article 201according to a further embodiment of the invention. Correspondingreference numerals are used for features of the smoking article 201which are the same as those of the smoking article 101 described withreference to FIG. 1, unless otherwise stated below.

As shown in FIG. 2a, 2b the smoking article 201 includes a filter 202and a rod of smokeable material 203.

In the embodiment shown in FIG. 2a, 2b , the smoke constituent reducingtechnology is targeted to a lateral region, which is a central region ofthe smoking article.

The filter 202 comprises a substantially cylindrical plug of filtermaterial 205 wrapped in a plugwrap 206 around its circumferentialsurface. The rod of smokeable material 203 is wrapped in a wrappingmaterial 204. The rod of smokeable material 203 is connectedlongitudinally to the filter 202 by tipping material 207 overlaying thefilter 202 and partially overlaying the wrapping material 204.

The rod of smokeable material 203 is circumscribed by a wrappingmaterial 204, as shown in FIG. 2a, 2b . The wrapping material 204 may bea cigarette paper. The rod of smokeable material 203 is connectedlongitudinally to the filter 202 by tipping material overlaying thefilter 202 and partially overlaying the wrapping material 204.

The rod of smokeable material 203 comprises a smokeable material, inthis case tobacco 208. The smokeable material 208 may in generalcomprise any suitable smokeable material or blend.

The rod of smokeable material 203 also comprises a smoke constituentreducing technology 209, which is capable of reducing the concentrationof a smoke constituent in smoke.

In the embodiment shown, the tobacco rod 203 comprises a smokeconstituent reducing technology in the form of a thread 210 disposedwithin the tobacco material 208. The thread and its method ofincorporation may be similar to that described in WO 96/14762 and WO2010/032032.

The thread 210 is positioned along a central longitudinal axis of therod 203.

The thread 210 extends continuously the whole length of the rod.

In the embodiment shown, the thread 210 comprises carbon in fibrousform, such as carbon fibre or carbonised fibre materials, for example,carbonised polyester or polyamide, such as described in WO 96/14762.

The carbon fibre threads 210 are generally used as a continuous strandso as to be easily incorporable into the tobacco rod 203 as part of acontinuous manufacturing operation.

The thread 210 may comprise a loosely assembled bundle or strand oftypically 1 to 30 micrometres diameter or larger.

The presence of the carbon fibre thread 210 may itself reduce theconcentration of the smoke constituent, but the thread may also be usedas a carrier, for example of a smoke constituent reducing technology209.

Any suitable smoke constituent reducing technology 209 may be carried bythe thread 210. For example, an additive 209 may be used, which may be asorbent such as, for example, particulate activated carbon material, ora catalyst such as a metal catalyst. Metals which are suitable forplating onto the thread 210 include, in successive layers, first copperthen silver; copper then gold; copper, silver then gold; copper, silverthen platinum; copper, silver, gold then platinum or other suitablemetals such as tin. Any other suitable metal or combination of metalsmay be used.

The additive 209 may be applied to the thread 210 by any suitablemethod. The smoke constituent reducing technology may be retained bothby surface adsorption on the thread material and by interstitialretention between the fibres of the bundle.

The additive 209 is capable of adsorbing a particular target smokeconstituent from smoke. The thread is positioned longitudinally alongthe centre of the smokeable material 208, and in this way, the additive209 is targeted to a position within the rod of smokeable material 203corresponding to the central lateral region of the smoking article.Smoking articles having this configuration may therefore be suitable foruse when the target smoke constituent has been found to be present in ahigher concentration in a central lateral region of the smoking articleversus another lateral region.

When the smoking article 201 of FIG. 2 is in use, combustion of the rodof smokeable material 203 generates smoke which is drawn through thesmoking article 201. The smoke constituent may be produced at a higherconcentration in the central lateral region and due to the targetedpositioning of the smoke constituent reducing additive 209 theconcentration of the smoke constituent may be reduced.

The targeted region may be varied by adjusting the position of thethread 210 within the smokeable material 208. For example, where thesmoke constituent has been found to be present at a higher concentrationin a non-central lateral position, the thread 210 may be positionedextending longitudinally in a non-central lateral region of the tobaccorod 203. For example, the rod of smokeable material 203 may comprise oneor more threads in a peripheral lateral region of the rod of smokeablematerial 203.

In other embodiments, for example where the smoke constituent has beenfound to be present at a higher concentration in more than one lateralposition, the thread 210 may be positioned extending longitudinally inmore than one lateral regions of the tobacco rod 203. For example, therod of smokeable material may comprise one or more threads extendinglongitudinally along two, three, or four lateral regions of the rod 203.The plurality of threads may comprise different additives 209, targetedtowards the same or different smoke constituents.

By means of the arrangement shown in FIG. 2, a smoke constituentreducing additive 209, 210 may be targeted to one or more specificlateral regions within the rod of smokeable material 203. Specifically,the position of the thread or threads 210 within the smokeable material208 may be arranged to substantially coincide with the lateral regionsat which a smoke constituent has been found to occur at a higherconcentration.

The arrangement of a plurality of smoke constituent reducing threads atseveral lateral positions in the requisite quantities, may be used tofacilitate reductions of smoke constituents at lateral positions wheresmoke constituents may be generated at both higher and lowerconcentrations, hence further lowering smoke constituent concentrationsgenerated at these positions.

In some embodiments, one or more threads may be used in combination withother smoke constituent reducing technologies as appropriate. Forexample, the wrapper 204 may be a wrapper comprising a smoke constituentreducing technology as described above in respect of the embodiment ofFIG. 1a , 1 b.

In accordance with embodiments of the type shown in FIG. 2a, 2b , thearrangement of two or more smoke constituent reducing technologies,which may be the same or different technologies, at two or more lateralpositions in the smoking article may be used to facilitate reductions ofsmoke constituents at lateral positions where smoke constituents may begenerated at both higher and lower concentrations. Specifically, thearrangement of the smoking article shown in FIG. 2 allows the accurateincorporation of one or more different smoke constituent reducingtechnologies into specific location(s) in the smoking article. Forexample, as described above, the one or more threads 210, the content ofthe smokeable material 208, and the wrapper 204, or any combination ofthese parts, may comprise one or more smoke constituent reducingtechnologies. The location of the technologies may be easily andaccurately controlled, by adjusting the materials used and the positionand number of threads 210, to target one or more smoke constituentsbased on prior measurements of the concentration of the smokeconstituents present at different locations when the smoking article isin use.

FIG. 3a, 3b is a schematic illustration of a smoking article 301according to a further embodiment of the invention. Correspondingreference numerals are used for features of the smoking article 301which are the same as those of the smoking article 101 described withreference to FIG. 1, unless otherwise stated below.

As shown in FIG. 3a, 3b the smoking article 301 includes a filter 302and a rod of smokeable material 303.

In the embodiment shown in FIG. 3a, 3b , the smoke constituent reducingtechnology is targeted to a lateral region, which is a central region ofthe smoking article.

The filter 302 comprises a substantially cylindrical plug of filtermaterial 305 wrapped in a plugwrap 306 around its circumferentialsurface. The rod of smokeable material 303 is wrapped in a wrappingmaterial 304. The rod of smokeable material 303 is connectedlongitudinally to the filter 302 by tipping material 307 overlaying thefilter 302 and partially overlaying the wrapping material 304.

The rod of smokeable material 303 comprises a smokeable material, inthis case tobacco 308. The smokeable material 308 may in generalcomprise any suitable smokeable material or blend.

The rod of smokeable material 303 also comprises a smoke constituentreducing technology 309 which is capable of reducing the concentrationof a smoke constituent in smoke. In the embodiment shown, the smokeconstituent reducing technology comprises particles of a smokeconstituent reducing additive 309.

As shown in FIG. 3a, 3b , the tobacco rod 303 comprises a plurality ofparticles of additive 309 disposed within the tobacco material 308,concentrated in a longitudinal region which extends continuously alongthe whole length of the rod 303.

The particulate additive material 309 may be applied to the smokeablematerial by any suitable method.

The additive 309 is capable of adsorbing a particular target smokeconstituent from smoke. The additive is positioned longitudinally alongthe centre of the smokeable material 308, and in this way, the additive309 is targeted to a position within the rod of smokeable material 303corresponding to the central lateral region of the smoking article.Smoking articles having this configuration may therefore be suitable foruse when the target smoke constituent has been found to be present in ahigher concentration in a central lateral region of the smoking articleversus another lateral region.

Other lateral regions of the rod of smokeable material 303, such as theperipheral lateral regions, may comprise a reduced amount of additive309, such that the additive 309 is concentrated in the central lateralregion. Alternatively, the other lateral regions of the rod of smokeablematerial 303 may comprise no additive 309.

In other embodiments, for example where the smoke constituent may befound to be present at a higher concentration in a non-central lateralposition, particles of additive 309 are disposed within the tobaccomaterial 308 extending longitudinally in a corresponding non-centralposition along the tobacco rod 303. For example, the rod of smokeablematerial may comprise additive in a peripheral lateral region of the rodof smokeable material 303.

In other embodiments, particles of additive 309 may additionally oralternatively be located within the smoking article 301 by beingincorporated into the wrapping material 304. For example, the additive309 may be adhered to the inner surface of the wrapping material 304, oradhered to a second inner wrapping material positioned within the outerwrapper 304. The second wrapper material may be a web material, such asa cellulosic paper web, or reconstituted tobacco sheet material. Theadditive 309 may be adhered to the wrapper 304, or an inner wrapper, asdescribed in WO 2007/104908 and may be present on both faces of theinner wrapper. Any suitable method may be used to apply the additive tothe wrapper 304. In other embodiments, the additive 309 may in addition,or alternatively, be incorporated within the structure of the wrapper304 or an inner wrapper, as described in WO 2010/043475.

The wrapper(s) may comprise a paper wrapper material, or an alternativematerial, such as a reconstituted tobacco material. In addition, thewrapper(s) may comprise particulate sorbent material as described in WO2010/043475 and WO 99/38396.

The second sheet may be coextensive with the first wrapper 304, or mayonly be provided at one or more discrete portions. The wrapping material304 may comprise, in addition or as an alternative to particles ofadditive, a different type of smoke constituent reducing technology,such as a diluent. The diluent may, for example be carried by sorbentmaterial within the wrapper, as described in WO 2010/043475.

In other embodiments, for example where the smoke constituent has beenfound to be present at a higher concentration in more than one lateralposition, particles of additive 309 are disposed within the tobaccomaterial 308 extending longitudinally along more than one lateral regionof the tobacco rod 303. For example, the rod of smokeable material maycomprise two, three, or four longitudinally extending lateral regions ofparticulate material.

In some embodiments, the additive 309 may comprise, instead or inaddition to particulate material, portions of the carbon fibre threadmaterial described above in respect of the embodiment shown in FIG. 2a ,2 b.

The additive 309 may be inserted into the smokeable material 308 duringformation of the rod of smokeable material 303.

When the smoking article 301 of FIG. 3 is in use, combustion of the rodof smokeable material 303 generates smoke which is drawn through thesmoking article 301. The smoke constituent may be produced at a higherconcentration in the central lateral region and due to the targetedpositioning of the smoke constituent reducing additive 309 theconcentration of the smoke constituent may be reduced.

In some embodiments, the particulate material 309 present in the rod ofsmokeable material are particles of a porous carbon material and thesmoke constituent reducing additive is carried within the pores of theporous material.

In some embodiments, heat from the combustion of the smokeable materialcauses the release of the additive from the porous particulate material.The porous material may also function as a smoke constituent reducingadditive.

Alternatively, or in addition, the particulate material 309 may beimpregnated with one or metals such as silver or copper, which may becapable of acting as a catalyst to remove or reduce smoke constituents.

By means of the arrangement shown in FIGS. 3a, 3b , a smoke constituentreducing additive 309 may be targeted to specific lateral regions withinthe rod of smokeable material 303. Specifically, the additive 309 may beincorporated into the rod of smokeable material at one or more lateralregions which substantially coincide with the lateral regions at which atarget smoke constituent has been found to occur at a higherconcentration.

The arrangement of one or a plurality of smoke constituent reducingadditives in the smoking article may be controlled to reduce theconcentration of the smoke constituent present at the one or more firstlateral regions at which the constituent has been found to occur at ahigher concentration. Optionally one or a plurality of smoke constituentreducing additives may also be included to target one or more secondlateral regions in which the smoke constituent has been found to occurat a lower concentration.

In accordance with embodiments of the type shown in FIG. 3a, 3b , thearrangement of two or more smoke constituent reducing technologies,which may be the same or different technologies, at two or more lateralpositions in the smoking article may be used to facilitate reductions ofsmoke constituents at lateral positions where smoke constituents may begenerated at both higher and lower concentrations. Specifically, thearrangement of the smoking article shown in FIG. 3 allows the accurateincorporation of one or more different smoke constituent reducingtechnologies into specific location(s) in the smoking article. Forexample, as described above, the one or more additives 309, the contentof the smokeable material 308, and the wrapper 304, or any combinationof these parts, may comprise one or more smoke constituent reducingtechnologies. The location of the technologies may be easily andaccurately controlled, by adjusting the materials used and the positionand quantity of additive 309, to target one or more smoke constituentsbased on prior measurements of the concentration of the smokeconstituents present at different locations when the smoking article isin use.

In some embodiments, the smoking article may comprise a combination ofdifferent smoke constituent reducing technologies. Different smokeconstituent reducing technologies may be used in combination asappropriate. For example, the wrapper 304 may be a wrapper comprising asmoke constituent reducing technology as described above in respect ofthe embodiment of FIG. 1a, 1b . In another example, a smoking articlemay comprise additive 309 in combination with one or more threads asdescribed above in respect of the embodiment of FIG. 2a, 2b .Alternatively, the co-axial arrangement of FIG. 1a, 1b may be used incombination with the particulate additive of FIG. 3a, 3b , and/or withone or more threads as described above in respect of the embodiment ofFIG. 2a , 2 b.

Without wishing to be bound by any theory, the effects of the smokeconstituent reducing technologies when longitudinally positioned atdifferent lateral regions in the smoking article may arise from a changein combustion and/or pyrolysis profile of the smoke components in theaerosols generated during the smoking process. This may be the result ofthe physical presence of these technologies in specific laterallocations within the smoking article, which may exert physicochemicaleffects on thermal processes within the combustion and/or pyrolysiszones, resulting in reductions of several smoke constituents. Forexample, the smoke constituent reducing technology may inherentlyminimise or eliminate the generation of target smoke constituents, andmeans of targeting the smoke constituent may include catalysis,absorption or other physical means, chemical reaction, and exothermic orendothermic means.

In smoking articles in which the smoke reducing technology is positioneddistal from the coal, such as in the filter, the smoke constituentreducing technology may inherently minimise or eliminate the generationof target smoke constituents. Means of targeting the smoke constituentmay include catalysis, absorption or other physical means, and by meansof chemical reaction.

As discussed in the specific Examples, co-axial cigarette constructionswhere longitudinal smoke constituent reducing technologies are locatedat different lateral positions demonstrate reductions in the level ofspecific targeted smoke constituents in comparison to control smokingarticles.

The methods and systems of the present disclosure, as described aboveand shown in the accompanying Figures, provide for improved smokingarticles and techniques for making the same. It will be apparent tothose skilled in the art that various modifications and variations canbe made to the smoking article and method of the disclosed embodimentswithout departing from the spirit and scope of the disclosedembodiments. Thus, it is intended that the present disclosure includesmodifications and variations that are within the scope of the subjectdisclosure and equivalents. The advantages and features of thedisclosure are of a representative sample of embodiments only, and arenot exhaustive and/or exclusive. They are presented only to assist inunderstanding and teach the claimed features. It is to be understoodthat advantages, embodiments, examples, functions, features, structures,and/or other aspects of the disclosure are not to be consideredlimitations on the disclosure as defined by the claims or limitations onequivalents to the claims, and that other embodiments may be utilisedand modifications may be made without departing from the scope and/orspirit of the disclosure. Various embodiments may suitably comprise,consist of, or consist essentially of, various combinations of thedisclosed elements, components, features, parts, steps, means, etc. Inaddition, the disclosure includes other inventions not presentlyclaimed, but which may be claimed in future.

The following examples are provided to illustrate the present inventionand should not be construed as limiting thereof.

Examples Experimental System and Procedure

A suitable experimental system for obtaining samples of gases from theburning portion of a smoking article at various times and at variouslocations within the smoking article, before, during and after a puff,is described below.

Untipped tobacco rods were prepared, 70 mm long and 8 mm in diameter.The cigarette paper had a permeability of 180 cm³ min⁻¹ (10 cm²)⁻¹ (10cm water)⁻¹, and the tobacco was cut at 56 cuts per inch. The cigaretteswere selected for weight (0.99±0.02 g) and pressure drop (9.3±0.5 cmwater at an air flow of 17.5 cm³ s⁻¹), and were conditioned at 21° C.and 60% relative humidity.

The cigarettes were smoked in an atmosphere of 21% v/v oxygen/79% v/vargon inside a cubic Perspex chamber of 140 mm side. The gas mixture waspassed vertically through the chamber at a flow rate of 250 cm³ s⁻¹,equivalent to a linear velocity of 12.8 mm s⁻¹ or 0.18 miles per hourpast the cigarette. This is equivalent to a Beaufort force 0 aircondition (“calm air”). Under these conditions, the burn rates of thecigarette during the third puff, and in the preceding smoulder periodwere the same as when the cigarette was smoked in open air (1.29 and amean 0.069 mm s⁻¹ respectively). Furthermore, no decrease in the bulkconcentration of oxygen in the smoking chamber could be detected as thecigarette smouldered, or when puffs were taken. The puff by puff carbonmonoxide deliveries were effectively the same in the smoking chamber aswhen smoked in open air.

The smoke was withdrawn from the cigarette using a quartzprobe/thermocouple mounted radially into the cigarette, filtered using amini-Cambridge filter unit, and analysed using a quadrupole massspectrometer.

The gas concentrations during the third puff in the smoking regime wasdetermined, together with those during the smoulder period before andafter that puff. The cigarette was smoked singly in the smoking chamberusing a Cigarette Components Ltd. C.S.M. 10 smoking machine, taking a 35cm³ puff of 2 seconds duration, once per minute under restrictedsmoulder conditions. The pressure-time profile of the puff was square.

For a given position of the probe in the cigarette, at least fourreplicate experiments were performed. The mass spectrometer wassystematically calibrated before each replicate experiment, using knowngas mixtures. In successive experiments, the probe was inserted into thecigarette for distances of 0, 1, 2, 3 and 3.5 mm from the central axis,and at distances of between −10 and +10 from the line of paper burn atthe start of the puff (Table 1).

TABLE 1 INITIAL POSITIONS OF PROBE FOR THE INTERNAL CONTOURDETERMINATIONS* Distance From Central Axis of Cigarette (mm) Initial**Axial Distance (mm) from Paper Burn Line 0 −10 −6 −4 −2 0 2 4 6 8 10 1−10 −6 −4 −2 0 2 4 6 8 2 −10 −6 −4 −2 0 2 4 6 8 3 −10 −6 −4 −2 0 2 4 63.5 −10 −6 −4 −2 0 2 4 *Axial positions in the unburnt tobacco rod aregiven as negative distances from the line of paper burn, the burn lineis given the axial position of zero, and positions in the coal and ashare given as positive distances from the burn line. **The distance atthe start of the third puff in the smoking regime. During the puff, thepaper burn line moves down the tobacco rod with a linear speed of 1.29mm s⁻¹. For about 15 s after the end of the puff, the paper burn line isstationary; it them moves with a linear speed of 0.069 mm s⁻¹.

Results of Smoke Constituent Concentration Determination

Example gas concentration profiles obtained before, during and followinga 2-second puff for one position of the probe during the cigarette, areshown in FIG. 4. The profiles shown in FIG. 4 illustrates the gasconcentration as a function of time, from the start of the puff, oraxial distance from the burn line, for a given initial position of theprobe in the cigarette. The 95% confidence limits of each mean point(mean of four replicates) are also shown. These depend on the quantityof gas and the position in the smoking cycle.

Example contour distributions of temperature, oxygen, carbon monoxide,carbon dioxide, hydrogen and propane inside the combustion coal of thecigarette, at various stages during and following the third puff aregiven in FIGS. 5-10.

In FIGS. 5-10, the x-axis is the distance from the line of paper burn(mm) and the y-axis is the diameter of the cigarette (which was 8 mm).

The gas concentration contour distributions shown in FIGS. 5-10 areobtained from a combination of many profiles for different initial probepositions, and show the gas concentration distribution throughout thecoal at a given time point in the smoking cycle.

Alternate contours in each plot are marked with the value of thecontour, and the serrated contours represent valleys. The signconvention of the axial distances used in these diagrams is defined inthe first footnote to Table 1. The temperature distributions wereobtained using a thermocouple positioned at the end of the gas samplingprobe.

The concentration of the measured analytes (smoke constituents) can beseen to vary considerably across the width of the smoking article. Forexample, during puffing, oxygen levels drop from about 20% v/v to nearzero near the axial middle of the coal area, whereas carbon monoxidelevels generally are at their highest at this position. Carbon dioxidealso tends to be high in the axial middle coal area.

Most of the incoming oxygen during the puff appears to be consumedbefore it can reach the centre of the coal.

Propane concentration seems to be highest in almost symmetrically offset positions axially relative to the coal (FIGS. 5-9).

FIG. 10 illustrates the concentration profiles of the analytes 6 secondsfrom the start of a 2 second puff, (i.e. 4 seconds into the inter-puffsmouldering period). Again, oxygen levels approach zero axially in themiddle coal area, with carbon monoxide and carbon dioxide tending to beat highest levels in a central lateral region. Propane concentrationappears to be highest in symmetrically off set positions axiallyrelative to the coal.

Smoke Constituent Reducing Technologies

Following the observation that carbon monoxide levels are highest nearthe axial centre of the coal, it was hypothesised that smoke componentreducing technologies directed towards carbon monoxide would beeffective when longitudinally positioned in a central lateral region ofa cigarette.

Co-axial design cigarettes similar to those shown in FIG. 1 wereproduced in which smoke constituent reducing technologies directedtowards carbon monoxide were longitudinally positioned in centrallateral regions of a cigarette. For the purpose of this work, the term‘Smoke Constituent Reducing Technology’ is abbreviated to ‘SCRT’.

Two different smoke constituent reducing technologies were investigatedutilising a co-axial cigarette construction. The smoke constituentreducing technologies are described in Table 2.

TABLE 2 Smoke Constituent Reducing Technologies Smoke Constituent Typeof Reducing Technology Technology Description SCRT-A Catalyst Acigarette paper wrapper incor- porating iron oxide, with potential toreduce carbon monoxide levels SCRT-B Diluent A non-tobacco basedreconstituted material incorporating smoke dilu- tion technology whichis designed to dilute tobacco smoke with a smoke diluent, and hencedilute smoke constituents: this was incorporated into a tobacco blend

These technologies were included longitudinally within a co-axialcigarette design, in central lateral positions. The effect on smokechemistry was assessed by comparison with control co-axial cigarettesmanufactured from control materials.

Co-axial cigarettes similar to those described above and shown in FIG. 1were prepared. The cigarettes were constructed using either of twodifferent types of cigarette paper as the inner wrapper (111), andeither of two different types of smokeable material as the first (inner)smokeable material (114) in the inner rod (110).

The inner rod was a super-slim cigarette construction, having a diameterof about 17 mm. The outer diameter of the cigarettes was about 24-25 mm.The co-axial cigarettes were manufactured utilising two cigarette makingmachines in series, the super-slim tobacco rod from the first machinebeing fed into the second to enshroud this with an outer annulus ofsmokeable material and apply the outer overwrap.

The filters (102) of the cigarettes were non-ventilated.

According to FIG. 1, the outer annulus of smokeable material correspondsto a second smokeable material (115) in the outer rod (112), whichcircumscribes the inner rod (no).

The co-axial cigarette design requires both an inner and an outerwrapper (see FIG. 1, 111, 104). The outer wrapper used was the same forall of the cigarette samples studied, and consisted of 50 CUpermeability paper with a basis weight of 23 gsm. This paper is referredto as Cigarette Paper 2.

The inner rod wrapper (iii) used was variable in different cigarettesamples studied. The first type of wrapper, which was the controlwrapper and referred to as Cigarette Paper 1, was a 25 CU permeabilitypaper with a basis weight of 23 gsm. This wrapper did not comprise asmoke constituent reducing technology.

The second type of wrapper, referred to as “Iron Oxide Paper”, was a 45CU permeability iron oxide type paper where the iron oxide is used as afiller, manufactured by a commercial cigarette paper manufacturer. Thepaper had a basis weight of 26 gsm, with an iron oxide contentequivalent to 16.2% w/w iron.

The first type of smokeable material, referred to as ‘Blend 1’,comprises a blend of defined tobacco materials in known proportions.This blend did not comprise a smoke constituent reducing technology.

The second type of smokable material, referred to as ‘Diluent Blend’,comprises a mixture of Blend 1 and a sheet material containing a chalkbased band-cast sheet with the addition of substances to act as a smokediluent (‘Diluent Sheet’). The Diluent Sheet was blended at 50%inclusion by weight with ‘Blend 1’. The Diluent Blend incorporating theDiluent Sheet is designed to dilute the tobacco smoke (and hence smokeconstituents) with a smoke diluent—in this case the Diluent Sheetcontained triacetin and glycerol to act as smoke diluents. Thecomposition of the Diluent Sheet is presented in Table 3.

TABLE 3 Composition of the Diluent Sheet of the Diluent Blend Ingredient% (by weight) Chalk 71 Alginate 7.5 Caramel 1.5 Glycerol 3 Triacetin 17

Co-axial cigarettes were constructed to study the effect ofincorporating the smoke constituent reducing technologies longitudinallyin central lateral positions within the co-axial construction. Thefollowing cigarette designs were manufactured, which facilitated a studyof the technologies, individually and in combination, on smoke chemistrywhen compared to co-axial cigarettes made from control materials(control cigarettes). The co-axial cigarette design experimental matrixis given in Table 4.

TABLE 4 Co-axial Cigarette Design Experimental Matrix Lateral PositionLateral Position Cigarette Inner Outer Inner Outer Sample Blend BlendWrapper Wrapper Comment 1 Blend 1 Blend 1 Cigarette Cigarette Control(Control) Paper 1 Paper 2 Cigarette 2 Blend 1 Blend 1 Iron OxideCigarette SCRT-A Paper Paper 2 (SCRT-A) 3 Diluent Blend 1 CigaretteCigarette SCRT-B Blend Paper 1 Paper 2 (SCRT-B) 4 Diluent Blend 1 IronOxide Cigarette SCRT-A Blend Paper Paper 2 and SCRT-B (SCRT-B) (SCRT-A)

By comparing Cigarette 2 to Control 1, the effect of SCRT-A (Iron OxidePaper) may be ascertained.

By comparing Cigarette 3 to Control 1, the effect of SCRT-B (DiluentBlend) may be ascertained.

By comparing Cigarette 4 to Control 1, the combined effect of SCRT-A(Iron Oxide Paper) and SCRT-B (Diluent Blend) may be ascertained.

A cellulose acetate filter was used on all cigarettes. The filter wasnot ventilated. The cigarettes were manufactured to a firmness of about72% and not exceeding a pressure drop of 160 mmWG.

The cigarettes were smoked under ISO smoking regime, which is set out inTable 5.

TABLE 5 Smoking Regime Puff Volume (mL) Puff Duration (s) Puff Frequency(s) 35 2 60

The amounts of carbon monoxide and NFDPM present in the mainstream smokeproduced by the cigarettes were determined. The term ‘NFDPM’ is a termof art, determined utilising a test methodology as would be understoodby a skilled person. It is defined as the weight of mainstream smokeparticulate matter trapped on a high efficiency particulate filter,minus the weight of nicotine and water on the filter. It is usuallyexpressed in weight units of milligrams per cigarette.

The carbon monoxide content of the smoke was calculated as the ratio ofthe amount of carbon monoxide to the amount of NFDPM, and is shown inTable 6.

TABLE 6 Carbon Monoxide:NFDPM Ratio of Non-Tip Ventilated CigarettesCigarette CO:NFDPM Sample Ratio % change compared to Control 1 1 1.43Control 1 2 1.25 −12.59 3 1.08 −24.48 4 1.09 −23.78

It can be seen from Table 6 that for Cigarette Sample 2 incorporatingSCRT-A (Iron Oxide Paper) compared to Control 1, the level of carbonmonoxide is reduced relative to the level of NFDPM.

Likewise, for Cigarette Sample 3 incorporating SCRT-B (Diluent Blend)compared to Control 1, there is a reduction in the level of carbonmonoxide relative to the level of NFDPM.

Finally, the reduction in the level of carbon monoxide relative to thatof NFDPM is also demonstrated for Cigarette Sample 4, which incorporatesSCRT-A and SCRT-B, compared to Control 1.

Thus, the targeted incorporation of a smoke constituent reducingtechnology into a smoking article, based on the prior determination ofthe location of the greatest concentration of the smoke constituent,results in cigarette constructions having an increased capacity toreduce target smoke constituents relative to NFDPM.

In conclusion, the concentration of carbon monoxide, as an exemplarysmoke constituent, produced in a smoking article as it is in use wasdetermined at various lateral positions and at various time pointsduring puffing and between puffs. Carbon monoxide was found to beproduced at the highest concentrations in the central lateral region ofthe smoking article. Smoking articles were therefore produced comprisingone or a combination of two different smoke constituent reducingtechnologies positioned in substantially central lateral regions of thesmoking articles to target carbon monoxide. The effect of the smokeconstituent reducing technologies on the concentration of carbonmonoxide was investigated. The first smoke constituent reducingtechnology was a wrapper comprising iron oxide, positioned in anintermediate annular region of the smokeable material, and the secondsmoke constituent reducing technology was the use of a diluent blend inthe tobacco blend in a central lateral region of the smokeable material.The results obtained clearly show that the targeted positioning of smokeconstituent reducing technologies within a smoking article reduced theconcentration of carbon monoxide produced. This method provides a usefulnew tool to the smoking article designer.

1. A method of producing a smoking article which in use generates smokehaving a smoke constituent, wherein the smoking article comprises asmoke constituent reducing technology which is capable of reducing theconcentration of the smoke constituent, and wherein the methodcomprises: 1) determining one or more first lateral regions at which,when the smoking article is in use, the smoke constituent is present ata first concentration, and one or more second lateral regions at which,when the smoking article is in use, the smoke constituent is present ata second concentration which is lower than the first concentration; and,2) producing a smoking article in which the smoke constituent reducingtechnology is targeted to reduce the concentration of the smokeconstituent present at the one or more first lateral regions. 2.(canceled)
 3. A method according to claim 1, wherein the smokeconstituent reducing technology is located in the one or more firstlateral regions.
 4. A method according to claim 3, wherein a smokeconstituent reducing technology is also located in the one or moresecond lateral regions, and the amount of smoke constituent reducingtechnology located in the one or more first lateral regions is greaterthan the amount located in the one or more second lateral regions.
 5. Amethod according to claim 1, wherein the smoke constituent reducingtechnology is not located in the one or more second lateral regions. 6.A method according to claim 4, wherein the relative amounts of smokeconstituent reducing technology located in the first and second regionsis proportional to the relative first and second concentrations of thesmoke constituent.
 7. A method according to claim 1, wherein the smokingarticle further comprises a rod of smokeable material, and the first andsecond lateral regions are regions of the rod of smokeable material. 8.A method according to claim 7, wherein the rod of smokeable material isgenerally cylindrical in shape and the first and second lateral regionsare located on a diametrical line across the width of the cylinder.
 9. Amethod according to claim 1, wherein the smoking article furthercomprises a filter and the smoke constituent reducing technology islocated within the filter to reduce the concentration of the smokeconstituent present at the one or more first lateral regions.
 10. Amethod according to claim 1, wherein the smoking article furthercomprises a filter and the filter comprises portions of varying densityto create pressure drop regions to control airflow through the smokingarticle.
 11. A method according to claim 1, wherein the smoking articlecomprises two different smoke constituent reducing technologies.
 12. Amethod according to claim 11, wherein the two different smokeconstituent reducing technologies are located in the same one or morefirst lateral regions.
 13. A method according to claim 11, wherein thetwo different smoke constituent reducing technologies are located indifferent lateral regions.
 14. A method according to claim 1, whereinthe smoking article further comprises a co-axial rod comprising an innerrod of smokeable material circumscribed by an inner wrapper, the innerrod being circumscribed by an outer rod of smokeable materialcircumscribed by an outer wrapper.
 15. A method according to claim 14,wherein the inner wrapper is impermeable to the passage of smokeconstituents.
 16. A method according to claim 14, wherein the innerwrapper comprises the smoke constituent reducing technology.
 17. Amethod according to claim 14, wherein the smokeable material of theinner and/or outer rod comprises the smoke constituent reducingtechnology.
 18. A method according to claim 14, wherein the outerwrapper comprises the smoke constituent reducing technology.
 19. Amethod according to claim 14, wherein one of the inner or outer rods hasa higher density relative to the other rod to create a pressure drop tocontrol airflow through the smoking article.
 20. A method according toclaim 14, wherein the inner rod comprises a further inner rod ofsmokeable material circumscribed by a further inner wrapper.
 21. Amethod according to claim 1, wherein the smoking article furthercomprises a thread.
 22. A method according to claim 21, wherein thesmoking article further comprises a rod of smokeable material and thethread extends continuously within the smokeable material along thewhole length of the rod of smokeable material.
 23. A method according toclaim 1, wherein the smoking article comprises a rod of smokeablematerial, and wherein the smoke constituent reducing technologycomprises particles disposed within the rod of smokeable material.
 24. Amethod according to claim 23, wherein the particles are disposed withinthe smokeable material.
 25. A method according to claim 24, wherein theparticles are concentrated in a longitudinal region extending along therod of smokeable material.
 26. A method according to claim 23, whereinthe smokeable material is circumscribed by a wrapper and the particlesare adhered to the inner surface of the wrapper.
 27. A method accordingto claim 1, wherein the smoke constituent reducing technology is inparticulate or granular form.
 28. A method according to claim 1, whereinthe smoke constituent reducing technology comprises an additive.
 29. Amethod according to claim 28, wherein the additive is a sorbent or acatalyst.
 30. A method according to claim 1, wherein the smokeconstituent reducing technology comprises a diluent.
 31. A methodaccording to claim 1, wherein the smoke constituent reducing technologycomprises a smokeable material which in use generates a concentration ofthe smoke constituent which is lower than the concentration that isproduced by tobacco.
 32. A smoking article which in use generates smokehaving a smoke constituent, wherein the smoking article comprises asmoke constituent reducing technology which is capable of reducing theconcentration of the smoke constituent, and wherein in use the smokeconstituent is present at a first concentration in one or more firstlateral regions, and the smoke constituent is present at a secondconcentration which is lower than the first concentration in one or moresecond lateral regions, and wherein the amount of the technology that istargeted to reduce the concentration of the smoke constituent present atthe one or more first lateral regions, is greater than the amount of thetechnology that is targeted to reduce the concentration of the smokeconstituent present at the one or more second lateral regions.
 33. Asmoking article according to claim 32, wherein the smoke constituentreducing technology is located at the one or more first lateral regions.34. A smoking article according to claim 32, wherein the amount of smokeconstituent reducing technology located in the one or more first lateralregions is greater than the amount located in the one or more secondlateral regions.
 35. A smoking article according to claim 32, whereinthe smoking article further comprises a rod of smokeable material, andthe first and second lateral regions are regions of the rod of smokeablematerial.
 36. A smoking article according to claim 32, wherein thesmoking article further comprises a rod of smokeable material, andwherein the smoke constituent reducing technology comprises particlesdisposed within the rod of smokeable material.
 37. A smoking articleaccording to claim 36, wherein the particles are concentrated in alongitudinal region extending along the rod of smokeable material. 38.(canceled)
 39. A smoking article which in use generates smoke having asmoke constituent, wherein the smoking article comprises a smokeconstituent reducing technology which is capable of reducing theconcentration of the smoke constituent, and wherein the smoking articleis obtainable by a method comprising: 1) determining one or more firstlateral regions at which, when the smoking article is in use, the smokeconstituent is present at a first concentration, and one or more secondlateral regions at which, when the smoking article is in use, the smokeconstituent is present at a second concentration which is lower than thefirst concentration; and, 2) producing a smoking article in which theamount of the smoke constituent reducing technology that is targeted toreduce the concentration of the smoke constituent present at the one ormore first lateral regions is greater than the amount of the technologythat is targeted to reduce the concentration of the smoke constituentpresent at the one or more second lateral regions.
 40. A smoking articleaccording to claim 39, wherein the smoking article further comprises arod of smokeable material, and wherein the smoke constituent reducingtechnology comprises particles disposed within the smokeable material.